1. Field of the Invention
The present invention relates generally to mattresses for use in association with beds and other support platforms. The present invention relates more specifically to a foam containing mattress assembly having a pressure relieving structure comprising semi-independent foam pillars, a method of manufacture thereof, and a method of treating decubitus ulcers therewith.
2. Description of the Related Art
Patients and other persons restricted to bed for extended periods incur the risk of decubitus ulcers formation. Decubitus ulcers (also referred to as bed sores, pressure sores or pressure ulcers) are formed due to an interruption of blood flow in the capillaries below skin tissue due to pressure against the skin. The highest risk areas for such ulcer formation are those areas where there exists a bony prominence, which tends to shut down capillaries sandwiched between the bony prominence and the underlying support surface. When considering the redistribution of body weight and the formation of decubitus ulcers, historically, the trochanter (hip) and the heels are the body sites of greatest concern because these are the areas most frequently involved in decubitus ulcer formations which afflict bedridden or otherwise immobile patients. Generally, as is well known in the art, blood flows through the capillaries at an approximate pressure of 32 millimeters of mercury (mm Hg). This pressure can be somewhat lower for elderly individuals or individuals in poor health or with nutritional deficiencies. Once the net external pressure on a capillary exceeds its internal blood pressure, occlusion occurs, preventing the afflicted capillaries from supplying oxygen and nutrition to the skin in close proximity thereto. Tissue trauma may then set in with the resultant tissue decay and ulcer formation. Movement of the afflicted individual into different positions generally helps in restoring blood circulation into the effected areas. However, such movement is, either not always possible or is in some instances neglected.
Additionally, even shorter bed rest periods by healthy individuals on a mattress that does not relieve or reduce the pressure exerted on the user is likely to be considered uncomfortable. Conversely, a mattress that does not provide sufficient firmness or support is also likely to be uncomfortable.
In attempting to avoid the problem of decubitus ulcers in bedridden individuals and to provide greater user comfort to those spending substantial amounts of time in bed, a variety of techniques and devices have been used in the past. For instance, air mattress overlays, air mattresses (static and dynamic), water mattress overlays, water mattresses, gel-like overlays, specialty care beds, foam overlays and various types of other mattresses have been introduced in an attempt to avoid the above noted problems with decubitus ulcers and general user discomfort. Some relatively expensive motorized and/or dynamic devices have been quite successful in solving these problems. However, their cost and relative complexity drastically reduce the breadth of market to which such devices can be effectively offered.
Therefore, to date, no non mechanized device has been wholly successful in meeting these needs, at a cost which, in view of government cutbacks in such programs as Medicare, and stringent, and in some case draconian, cost restrictions, would make such devices readily accessible. The meeting of these needs, in a reasonably economical fashion, is the goal of the present invention.
The present invention provides a non-mechanized mattress assembly that possesses a plurality of semi-independent foam pillars comprising an upper portion of the mattress. This mattress assembly may be fabricated from a single piece of deformable material, such as foam, or, in the presently preferred embodiment, comprises a plurality of core components, for example, a foam base, a foam body support cushion, and a foot cushion insert, which are placed in a contiguous operatively coactive manner. In a multiple component embodiment, these components may be held in place by appropriate contouring of their structures, may be bonded together, or may be fixedly attached in any other suitable manner as is presently known in the art, so as to fix their relative orientation.
Once so placed, or assembled, or in the single component embodiment, after fabrication, a removable fabric cover envelops this mattress core assembly. Most usually, the completed mattress core is generally rectangular in shape.
In the multiple component embodiment, the base component supports the other elements of the mattress core, and, therefore has the same lateral and longitudinal dimensions, as does the entire assembled mattress core. The overall height of the covered mattress assembly, in either the single component, or the multiple component embodiment will generally approximate the thickness of a present day medical mattress, from about 5 to about 7 inches. The height (or depth) of the base generally ranges from about 1 to about 2 inches, except as may be necessitated by any applicable contouring requirements. The base is less deformable than is either the body support cushion or the foot support insert. Though the base is generally symmetrical, during the process of placing the components into alignment, one of the short edges of the base is designated as the top edge of the base, and thereby also of the assembled mattress core.
The body support cushion component is made from a rectangular solid foam element whose upper surface is cut into a plurality of solid pillars, which are most commonly arranged in some systematic manner. This cushion is longitudinally symmetrical about its central longitudinal axis. In the presently preferred embodiment, the rectangular solid pillars are grouped into a central array comprising pillars with generally square top surfaces, and edge rows of rectangular solid pillars having rectangular top faces. Making repeated cuts into the top of the body cushion creates these pillars. The depth of the cuts into the surface of the body support cushion is preferably approximately one half to three quarters of the shortest dimension of the face of the pillar, or roughly one third to two thirds the overall thickness of the body support cushion, in the multi component embodiment.
The foot cushion insert, in the multi component embodiment, is a generally trapezoidal geometric solid comprised of polyurethane foam, or other suitable material, which could include air, or other fluid. This trapezoid is oriented so that its thickness is greater in that portion proximate to the body support cushion, and lesser in that portion remote from the body support cushion, thereby resulting in the insert having a thick edge and a thin edge, and a downward slope from the direction of the designated top edge of the mattress, to the designated bottom edge of the mattress.
Viewed from the top, the trapezoid is substantially rectangular in shape. The insert is, most usually, more easily deformable than both the base and the body support cushion. The same slope will generally be fabricated into the single component embodiment, in the same relative location.
The multiple component embodiment of the present invention is assembled in the following manner. The base is placed in the desired orientation. The body support cushion is aligned so that the top edge of the cushion is in registry with the selected top edge of the base. The foot insert is then placed so that the thick edge of the insert abuts the bottom edge of the body support cushion, the thin edge of the insert is in registry with the bottom edge of the base, and the sides of the assembled cushion are in substantial registry with the sides of the base. The base, body support cushion, and insert, are then secured in position.
A zippered fabric cover then removeably envelops the assembled mattress core. The resultant structure defines a plurality of semi-independently compressible pillars that provide appropriate support to the upper portion of a person in a supine, or reclining position on the mattress, and an inclined uniform surface that supports the feet and connective portions of the person in question.
An object of the present invention is to provide a non-mechanized pressure-reducing mattress that provides therapeutic benefits to a person confined thereto for a substantial period.
Another object of the present invention is to provide a mattress, which prevents or minimizes capillary damage to those who are confined thereto.
A further object of the present invention is to provide a reasonably economical pressure relieving mattress that provides therapeutic benefits to a mammal confined thereto for a substantial period.
Yet another object of the present invention is to provide a relatively lightweight pressure-relieving mattress.
A still further object of the present invention is to provide a mattress, that, when hot wires are used to cut the slots which create the semi-independent pillars, is easy and relatively affordable to manufacture.
Still another object of the present invention is to provide a method of alleviating or minimizing the occurrence of decubitus ulcers on a person confined to a bed for a significant period of time, by the use of the semi-independent pillar containing mattress disclosed herein.
A yet further object of the present invention is to provide a decubitus preventing or alleviating mattress containing semi-independent pressure relieving pillars which is more economical than those of equal efficacy known to the prior art.
These and still further objects as shall hereinafter appear are readily fulfilled by the novel pressure relieving mattress of the present invention in a remarkably unexpected manner as will be readily discerned from the following detailed description of an exemplary embodiment thereof especially when read in conjunction with the accompanying drawings in which like parts bear like numerals throughout the several views.